Computational Approaches and Observer Variation in the 3D Musculoskeletal Modeling of the Heads of Anolis.

High-resolution imaging, 3D modeling, and quantitative analyses are equipping evolutionary biologists with new approaches to understanding the variation and evolution of the musculoskeletal system. However, challenges with interpreting DiceCT data and higher order use of modeled muscles have not yet been fully explored, and the error in and accuracy of some digital methods remain unclear. West Indian Anolis lizards are a model clade for exploring patterns in functional adaptation, ecomorphology, and sexual size dimorphism in vertebrates. These lizards possess numerous jaw muscles with potentially different anatomies that sculpt the adductor chamber of the skull. Here we test approaches to quantifying the musculoskeletal shape of the heads of two species of Anolis: A. pulchellus and A. sagrei. We employ comparative approaches such as DiceCT segmentation of jaw muscles, 3D surface attachment mapping, and 3D landmarking with the aim of exploring muscle volumes, 3D muscle fiber architecture, and sexual dimorphism of the skull. We then compare sources of measurement error in these 3D analyses while also presenting new 3D musculoskeletal data from the Anolis feeding apparatus. These findings demonstrate the accessibility and repeatability of these emerging techniques as well as provide details regarding the musculoskeletal anatomy of the heads of A. pulchellus and A. sagrei which show potential for further research of comparative biomechanics and evolution in the clade.

First Report of Black Root Rot Caused by Thielaviopsis basicola on Soybean (Glycine max) in Arkansas.

Thielaviopsis basicola (Berk. & Broome) Ferraris (synonym Chalara elegans Nag Raj & Kendrick) is a soilborne plant-pathogenic fungus reported in many parts of the world. In Arkansas, T. basicola is found commonly in cotton fields (4). This fungus colonizes cortical tissue of seedlings under cool wet conditions, causing a dark brown or black discoloration of the roots and hypocotyls, resulting in stunted, slow-developing plants (4). In 2008, large areas of stunted soybean plants with shortened internodes were reported in a field in Phillips County, AR, where cotton had previously been produced. Soybean was planted in this field in early April when cool soil temperatures (~21 to 24°C) prevailed. Soybean plants at the v3 to v5 growth stages were observed to have extensive areas of black cortical root necrosis. Plant samples were collected and roots were excised, washed, and surface disinfested in a 10% NaOCl solution. Root segments were incubated on the carrot-based selective medium TB-CEN (3). T. basicola was isolated from incubated segments after 2 weeks at 21°C in the dark. Chlamydospore chains (44.8 to 56.0 × 8.4 to 11.2 µm) consisting of an average of six spores and endoconidia (8 to 30 × 3 to 5 µm) were observed with a compound microscope. In addition to plant tissue, soil was assayed and confirmed to be positive for T. basicola by the pour plate technique (3) with the medium TB-CEN. Greenhouse trials were conducted to confirm field observations. Soil from the Phillips County field was sterilized and reinfested with 100 CFU of chlaymdospore suspension per gram (dry weight) of soil. Fifty soybean seeds (cv. Schillinger 457) were planted in infested and sterilized soil and grown for 29 days. Results showed that 38% of plants germinated and survived in the T. basicola-infested soil compared with 71% in the sterile soil treatment. Fifteen of the nineteen plants that survived in the infested soil were positive for T. basicola, while all plants in the sterilized soil were negative for the fungus. Soybean has previously been reported to be a host of T. basicola worldwide, but North American reports have been confined to Canada and Michigan, where cool soil temperatures persist for longer periods during the early part of the growing season (1,2). To our knowledge, this is the first report of T. basicola being important in the growth of soybean in warmer latitudes where the pathogen has been observed frequently on cotton and tobacco. In areas where cotton has historically suffered seedling damage from T. basicola, black root rot may become important on soybean as production of the latter crop increases. Since the initial field observation and confirmation in 2008, multiple soybean fields in 10 Arkansas counties have been documented with black root rot, with an estimated 5 to 30% of plants in each field infected. References: (1) T. R. Anderson. Can. J. Plant Pathol. 6:71, 1984. (2) J. L. Lockwood et al. Plant Dis. Rep. 54:849, 1970. (3) L. P. Specht and G. J. Griffin. Can. J. Plant Pathol. 7:438, 1985. (4) N. R. Walker et al. Phytopathology 89:613, 1999.

Microbial fuel cell biosensor for in situ assessment of microbial activity.

Microbial fuel cell (MFC)-based sensing was explored to provide useful information for the development of an approach to in situ monitoring of substrate concentration and microbial respiration rate. The ability of a MFC to provide meaningful information about in situ microbial respiration and analyte concentration was examined in column systems, where Geobacter sulfurreducens used an external electron acceptor (an electrode) to metabolize acetate. Column systems inoculated with G. sulfurreducens were operated with influent media at varying concentrations of acetate and monitored for current generation. Current generation was mirrored by bulk phase acetate concentration, and a correlation (R(2)=0.92) was developed between current values (0-0.30 mA) and acetate concentrations (0-2.3 mM). The MFC-system was also exposed to shock loading (pulses of oxygen), after which electricity production resumed immediately after media flow recommenced, underlining the resilience of the system and allowing for additional sensing capacity. Thus, the electrical signal produced by the MFC-system provided real-time data for electron donor availability and biological activity. These results have practical implications for development of a biosensor for inexpensive real-time monitoring of in situ bioremediation processes, where MFC technology provides information on the rate and nature of biodegradation processes.

Microbial fuel cell technology for measurement of microbial respiration of lactate as an example of bioremediation amendment.

Microbial fuel cell (MFC) based sensing was explored to provide for the development of an in situ bioremediation monitoring approach for substrate concentrations and microbial respiration rates. MFC systems were examined in column systems where Shewanella oneidensis MR1 used an external electron acceptor (an electrode) to metabolize lactate (a bioremediation additive) to acetate. Column systems were operated with varying influent lactate concentrations (0-41 mM) and monitored for current generation (0.01-0.39 mA). Biological current generation paralleled bulk phase lactate concentration both in the influent and in the bulk phase at the anode; current values were correlated to lactate concentration at the anode (R(2) = 0.9), The electrical signal provided real-time information for electron donor availability and biological activity. These results have practical implications for efficient and inexpensive real-time monitoring of in situ bioremediation processes where information on substrate concentrations is often difficult to obtain and where information on the rate and nature of metabolic processes is needed.

C60 in water: nanocrystal formation and microbial response.

Upon contact with water, under a variety of conditions, C60 spontaneously forms a stable aggregate with nanoscale dimensions (d = 25-500 nm), termed here "nano-C60". The color, hydrophobicity, and reactivity of individual C60 are substantially altered in this aggregate form. Herein, we provide conclusive lines of evidence demonstrating that in solution these aggregates are crystalline in order and remain as underivatized C60 throughout the formation/stabilization process that can later be chemically reversed. Particle size can be affected by formation parameters such as rates and the pH of the water addition. Once formed, nano-C60 remains stable in solution at or below ionic strengths of 0.05 I for months. In addition to demonstrating aggregate formation and stability over a wide range of conditions, results suggest that prokaryotic exposure to nano-C60 at relatively low concentrations is inhibitory, indicated by lack of growth (> or = 0.4 ppm) and decreased aerobic respiration rates (4 ppm). This work demonstrates the fact that the environmental fate, distribution, and biological risk associated with this important class of engineered nanomaterials will require a model that addresses not only the properties of bulk C60 but also that of the aggregate form generated in aqueous media.

The use of explant lens culture to assess cataractogenic potential.

Explanted cultures of crystalline lenses have been used to investigate mechanisms of xenobiotic-induced cataract formation. However, very few studies have utilized mechanistic information to predict the cataractogenic potential of structurally diverse xenobiotics. The present investigation outlines how visual assessment of lens clarity, biochemical endpoints of toxicity, and mechanisms of lenticular opacity formation can be used to select compounds with a lower probability of causing cataract formation in vivo. The rat lens explant culture system has been used to screen thiazolidinediones against ciglitazone for their direct cataractogenic potential in vitro. The two compounds that were selected as development candidates (englitazone and darglitazone) did not produce cataracts in rats exposed daily for 3 months. The culture system has also been used to illustrate that the lens is capable of metabolizing compounds to reactive intermediates. In this example, the toxicity of S-(1,2-dichlorovinyl)-L-cysteine (DCVC), a model cataractogen, was attenuated by inhibiting lenticular cysteine conjugate beta-lyase metabolism using aminooxyacetic acid. Finally, this model was used retrospectively to investigate the cataractogenic potential of CJ-12,918 and CJ-13,454 in rats. These compounds showed differences in the incidence of cataract formation in vivo based on differences in hepatic metabolism and penetration of parent drug and metabolites into the lens. The rank order of cataractogenic potential in vitro correlated better with in vivo results when an induced S9 microsomal fraction was added to the culture media. However, the model did not correctly predict the cataractogenic potential of ZD2138, a structurally similar compound. These studies illustrate the use of explant culture to assess mechanisms of cataract formation and outline its use and limitations for predicting cataractogenic potential in vivo.

Clinical score for predicting recurrence after hepatic resection for metastatic colorectal cancer: analysis of 1001 consecutive cases.

OBJECTIVE: There is a need for clearly defined and widely applicable clinical criteria for the selection of patients who may benefit from hepatic resection for metastatic colorectal cancer. Such criteria would also be useful for stratification of patients in clinical trials for this disease. METHODS: Clinical, pathologic, and outcome data for 1001 consecutive patients undergoing liver resection for metastatic colorectal cancer between July 1985 and October 1998 were examined. These resections included 237 trisegmentectomies, 394 lobectomies, and 370 resections encompassing less than a lobe. The surgical mortality rate was 2.8%. RESULTS: The 5-year survival rate was 37%, and the 10-year survival rate was 22%. Seven factors were found to be significant and independent predictors of poor long-term outcome by multivariate analysis: positive margin (p = 0.004), extrahepatic disease (p = 0.003), node-positive primary (p = 0.02), disease-free interval from primary to metastases <12 months (p = 0.03), number of hepatic tumors >1 (p = 0.0004), largest hepatic tumor >5 cm (p = 0.01), and carcinoembryonic antigen level >200 ng/ml (p = 0.01). When the last five of these criteria were used in a preoperative scoring system, assigning one point for each criterion, the total score was highly predictive of outcome (p < 0.0001). No patient with a score of 5 was a long-term survivor. CONCLUSION: Resection of hepatic colorectal metastases may produce long-term survival and cure. Long-term outcome can be predicted from five criteria that are readily available for all patients considered for resection. Patients with up to two criteria can have a favorable outcome. Patients with three, four, or five criteria should be considered for experimental adjuvant trials. Studies of preoperative staging techniques or of adjuvant therapies should consider using such a score for stratification of patients.

Ninety-six five-year survivors after liver resection for metastatic colorectal cancer.

BACKGROUND: Studies have consistently confirmed the benefit of liver resection for metastatic colorectal cancer. Few reports, however, have a long enough followup or sufficient 5-year survivors to study the clinical course of patients beyond 5 years. STUDY DESIGN: From July 1985 through December 1991, 456 patients underwent liver resection for colorectal metastases. Ninety-six actual 5-year survivors (21%) were identified and their clinical course retrospectively reviewed. RESULTS: Five-year survivors (n = 96) were more likely to have a Duke's B primary colorectal carcinoma, fewer than four metastatic lesions, unilobar disease, and a negative histologic margin when compared with patients not surviving 5 years (n = 298). Forty-four (46%) of the 96 five-year survivors had a recurrence after hepatectomy. Of these 44, 19 (43%) were rendered disease free after further treatment. Overall, 71 of the 96 five-year survivors were free of disease at last followup. The actuarial 10-year survival of this group was 78%. CONCLUSIONS: Patients that are disease free 5 years after liver resection are likely to have been cured by liver resection. Patients should be aggressively followed for recurrence because of the potential for further treatment and longterm survival.

Hepatic resection for noncolorectal, nonneuroendocrine metastases: a fifteen-year experience with ninety-six patients.

BACKGROUND: The role of liver resection for hepatic metastases from noncolorectal, nonneuroendocrine (NCNN) cancers is unknown. This study examines a large, single institutional experience of hepatic resection for NCNN metastases. METHODS: Records of 96 patients who underwent liver resection for metastatic NCNN cancer from 1980 to 1995 at a single institution were reviewed. Survival after liver resection in this cohort of patients is reported, and factors predictive of survival are analyzed. RESULTS: Resection was performed for liver metastases from genitourinary primary tumors (n = 34), soft tissue primary tumors (n = 41), and metastases from other primary cancers (n = 21). Extent of liver resection included wedge (n = 32), lobectomy (n = 44), and extended hepatic lobectomy (n = 20). No operative deaths occurred. Overall survival rate after resection at 1, 3, and 5 years was 80%, 45% and 37%, respectively (median survival, 32 months), with 12 actual 5-year survivors. There was no difference in survival according to the type of liver resection, bilateral versus unilateral disease, or resection of extrahepatic disease. Disease-free interval of less than 36 months before discovery of liver metastases, curative resection, and primary tumor group (genitourinary was greater than soft tissue, which was greater than gastrointestinal) were predictors of a significantly better survival by multivariate analysis. CONCLUSIONS: Primary tumor type, disease-free interval, and curative resection predict those patients who benefit from hepatic resection. Hepatic resection for patients with NCNN metastasis has value in carefully selected patients.

Liver resection for colorectal metastases.

PURPOSE: More than 50,000 patients in the United States will present each year with liver metastases from colorectal cancers. The current study was performed to determine if liver resection for colorectal metastases is safe and effective and to evaluate predictors of outcome. MATERIALS AND METHODS: Data for 456 consecutive resections performed between July 1985 and December 1991 in a tertiary referral center were analyzed. RESULTS: The perioperative mortality rate was 2.8%, with a mortality rate of 4.6% for resections that involved a lobectomy or more. The median hospital stay was 12 days and only 9% of patients were admitted to the intensive care unit. The 5-year survival rate is 38%, with a median survival duration of 46 months. By univariate analysis, nodal status of the primary lesion, short disease-free interval before detection of liver metastases, carcinoembryonic antigen (CEA) level greater than 200 ng/mL, multiple liver tumors, extrahepatic disease, large tumors, or positive resection margin was predictive of poorer outcome. Sex, age greater than 70 years, site of primary tumor, or perioperative transfusion was not predictive of outcome. By multivariate analysis, positive margin, size greater than 10 cm, disease-free interval less than 12 months, multiple tumors, and extrahepatic disease were independent predictors of poorer outcome. Short disease-free interval or multiple tumors were nevertheless associated with a 5-year survival rate greater than 24%. CONCLUSION: Liver resection for colorectal metastases is safe and effective therapy and currently represents the only potentially curative therapy for metastatic colorectal cancer. The only absolute contraindication to resection is extrahepatic disease. A randomized trial to examine efficacy of surgical resection cannot ethically be performed. Liver resection should be considered standard therapy for all fit patients with colorectal metastases isolated to the liver.

Outcome of treatment for distal bile duct cancer.

All patients with distal bile duct tumours over a 10-year period (October 1983 to December 1993) were identified by means of a prospective database. The medical records of 104 patients were reviewed. Univariate and multivariate analysis for predictors of outcome was performed. Median age of the patients was 65 (range 30-89) years. Patients presented with a clinical picture indistinguishable from that of pancreatic ductal adenocarcinoma. Twenty patients had no surgical treatment and 23 had a diagnostic laparotomy only. Biliary bypass was performed in 16 patients and radical resection was performed in 45 (pancreaticoduodenectomy, 39; bile duct excision, six). Operative mortality occurred in two of 45 patients having radical resection and complications in 17. Resection provided significant survival benefit. By univariate and multivariate analysis, resectability and negative node status (P < 0.001) were the only predictors of favourable outcome. Sex, age, preoperative stenting, grade of tumour and bilirubin level did not predict outcome. The 5-year survival rate for radically resected, node-negative tumours was 54 per cent. Surgical resection is effective therapy for distal bile duct tumours. These patients have a better outlook than those having resection of pancreatic adenocarcinoma.

Long-term results after resection for gallbladder cancer. Implications for staging and management.

BACKGROUND: The surgical management of gallbladder cancer is controversial. There is no consensus among surgeons as to the indications for reoperation or radical resection. OBJECTIVE: The purpose of this study was to examine results of reoperation after an incidental finding of gallbladder cancer after cholecystectomy, and results of radical resection in patients with advanced disease. METHODS: A retrospective review of 149 patients with the diagnosis of gallbladder cancer treated from 1985 to 1993 was performed. Fifty-eight patients were explored and 23 underwent resection for cure. Resection included trisegmentectomy in nine patients and bile duct resection in ten patients. Seventeen patients underwent re-exploration after an incidental finding of gallbladder cancer at initial cholecystectomy. RESULTS: Surgical resection is associated with an actuarial 51% 5-year disease-free survival rate, with a median follow-up time of 48 months. Eight patients are alive beyond 50 months. There were no operative deaths; the perioperative morbidity rate was 26%. Nodal status is the most powerful predictor of outcome. Two patients with T4, NO disease are alive without evidence of disease beyond 4 years. Thirteen of the 17 patients (76%) undergoing reoperation after simple cholecystectomy for T2 or T3 tumors had residual disease. CONCLUSIONS: Patients with nodal metastasis beyond the pericholedochal nodes should not be considered for curative resection. Tumors staged T4, NO should be included with stage III disease, and resection should be considered. Re-resection of T2 or T3 tumors after simple cholecystectomy is likely to include residual disease and should thus provide the only chance for long-term survival.

Erythromycin stimulates gastric emptying after esophagectomy with gastric replacement: a randomized clinical trial.

UNLABELLED: Delayed gastric emptying after esophagogastrectomy can pose a significant early postoperative problem. Because erythromycin, which stimulates the gastric antral and duodenal motilin receptor, has been shown to significantly increase gastric emptying in patients with diabetic gastroparesis, we decided to evaluate its effect on gastric emptying after esophagogastrectomy. METHODS: Twenty-four patients (18 men and six women, age range 41 to 79 years, median 66 years) were randomized to receive either erythromycin lactobionate (200 mg in 50 ml normal saline solution intravenously) (n = 13) or placebo (50 ml normal saline solution intravenously (n = 11) 11 days after esophagogastrectomy (with pyloric drainage procedure). After erythromycin or placebo had been infused over a 15-minute period, patients ingested a solid meal (scrambled egg with bread) labeled with technetium 99m sulfur colloid (500 microCi) over approximately 15 minutes. Dynamic images of the stomach were then acquired over 90 minutes in the supine position by gamma imaging. Results were expressed as percentage of counts retained in the stomach (percent gastric retention) over time. RESULTS: There were no side effects of erythromycin. In the placebo group, the mean percent of radiolabeled meal retained in the stomach after 90 minutes was 88%, which was significantly greater than in the erythromycin group, 37% (p < 0.001). In addition, analysis of covariance demonstrated that the rate of gastric emptying (slope of the line) was significantly greater in the erythromycin-treated group than in the placebo group (p < 0.0001). CONCLUSION: Early satiety after esophagogastrectomy may be due to delayed gastric emptying and not due to a decrease in the gastric reservoir. Intravenous erythromycin significantly improves gastric emptying in patients after esophagogastrectomy by stimulating gastric motility.

Tumor size is the primary prognosticator for pancreatic cancer after regional pancreatectomy.

OBJECTIVE: The purpose of this study was to evaluate the regional pancreatectomy as surgical therapy for ductal adenocarcinoma of the pancreas and to evaluate potential prognostic factors. SUMMARY BACKGROUND DATA: Regional pancreatectomy was developed as a more adequate surgical procedure for pancreatic cancer in an attempt to improve the cure rate for this highly lethal disease. Few studies have evaluated large numbers of patients treated with this technique, and in recent years the emphasis has been on more limited surgery for pancreatic cancer. METHODS: Fifty-six patients with ductal adenocarcinoma of the pancreatic head were treated by regional subtotal or total pancreatectomy. Clinical and pathologic parameters were reviewed and potential prognostic factors were compared statistically. The three patients who died within 30 days of the operation were excluded from the survival analysis. RESULTS: Primary tumor size was the strongest determinant of prognosis. The mean tumor size was 3.9 cm (range, 1-7 cm). Eighty-five percent of patients had peripancreatic soft tissue invasion microscopically, and 58% had regional lymph node metastasis. Kaplan-Meier survival curves indicated a 33% 5-year survival for patients with tumor 2.5 cm or less in diameter (n=12) and 12% for patients with larger tumors (n=39). No patient with a tumor larger than 5 cm survived more than 5 years. Mean tumor size was not significantly associated with lymph node metastases, but 5 of 12 patients (42%) with primary tumor < or =2.5 cm had lymph node metastases. Twenty-four percent of patients with negative lymph nodes and 14% with positive lymph nodes survived 5 years. The difference was not statistically significant (p=0.3), but this is likely related to sample size. The 30- day operative mortality was 5.3%. The most common complications were infection, gastrointestinal bleeding, and gastric stasis. CONCLUSIONS: After regional pancreatectomy, tumor size is the strongest predictor of prognosis. A multi- institutional randomized prospective trial of regional pancreatectomy versus pancreaticoduodenectomy is warranted in previously untreated, noninfected cases.

Pancreatic or liver resection for malignancy is safe and effective for the elderly.

BACKGROUND: Liver resection, or pancreaticoduodenectomy, has traditionally been thought to have a high morbidity and mortality rate among the elderly. Recent improvements in surgical and anesthetic techniques, an increasing number of elderly patients, and an increasing need to justify use of limited health care resources prompted an assessment of recent surgical outcomes. METHODS: Five hundred seventy-seven liver resections (July 1985-July 1994) performed for metastatic colorectal cancer and 488 pancreatic resections (October 1983-July 1994) performed for pancreatic malignancies were identified in departmental data bases. Outcomes of patients younger than age 70 years were compared with those of patients age 70 years or older. RESULTS: Liver resection for 128 patients age 70 years or older resulted in a 4% perioperative mortality rate and a 42% complication rate. Median hospital stay was 13 days, and 8% of the patients required admission to the intensive care unit (ICU). Median survival was 40 months, and the 5-year survival rate was 35%. No differences were found between results for the elderly and those for younger patients who had undergone liver resection, except for a minimally shorter hospital stay for the younger patients (median, 12 days vs. 13 days; p = 0.003). Pancreatic resection for 138 elderly patients resulted in a mortality rate of 6% and a complication rate of 45%. Median stay was 20 days, and 19% of the patients required ICU admission, results identical to those for the younger cohort. Long-term survival was poorer for the elderly patients, with a 5-year survival rate of 21% compared with 29% for the younger cohort (p = 0.03). CONCLUSIONS: Major liver or pancreatic resections can be performed for the elderly with acceptable morbidity and mortality rates and possible long-term survival. Chronological age alone is not a contraindication to liver or pancreatic resection for malignancy.

Factors affecting long-term outcome after hepatic resection for hepatocellular carcinoma.

BACKGROUND: Experience with hepatocellular carcinoma (HCC) is limited in the West and factors affecting outcome after resection are not clearly defined. METHODS: Between 1970 and 1992, 106 patients (including 74 Caucasians, 31 Orientals, and 1 black) underwent hepatic resection for HCC at Memorial Sloan-Kettering Cancer Center. Clinical and histopathologic factors of outcome were analyzed. RESULTS: Cirrhosis was present in 33% and 95% were Child-Pugh A. Operative mortality was 6%, 14% in cirrhotics versus 1% in non-cirrhotics (P = 0.013). Orientals had a higher prevalence of cirrhosis (68% versus 19%) (P < 0.0001) and smaller tumors (mean 8.7 cm versus 11.0 cm) (P = 0.028) compared to Caucasians. Overall survival was 41% and 32% at 5 and 10 years, respectively. By univariate analysis, survival was greater in association with the following: absence of vascular invasion (69% versus 28%, P = 0.002); absence of symptoms (66% versus 38%, P = 0.014); solitary tumor (53% versus 28%, P = 0.014); negative margins (46% versus 21%, P = 0.022); small tumor (< or = 5 cm) (75% versus 36%, P = 0.027); and presence of tumor capsule (69% versus 35%, P = 0.047). Ethnic origin, cirrhosis, necrosis and grade did not affect survival. By multivariate analysis, only vascular invasion predicted outcome (P = 0.0025, risk ratio 2.9). CONCLUSIONS: One third of patients resected for HCC can be expected to survive long-term. Except for a higher incidence of cirrhosis in Orientals, no major histopathologic or prognostic differences were noted between Orientals and Caucasians undergoing resection. Early cirrhosis (Child-Pugh A) did not adversely affect survival. Vascular invasion predicted long-term outcome.

Repeat hepatic resections for metastatic colorectal cancer.

OBJECTIVE: The authors weighed the risks and benefits of repeat liver resections for colorectal metastatic disease. METHOD: In the 6-year period between January 1985 and June 1991, 499 patients underwent liver resections for colorectal metastases at the Memorial Sloan-Kettering Cancer Center. Of these, 25 patients had repeat surgical resections for isolated recurrent disease to the liver. The clinical data for these patients were reviewed. RESULTS: The median interval between the two resections was 11 months. There were no perioperative deaths, and the complication rate was 28%. Median follow-up after the second liver resection is 19 months, with median survival of 17 months for nonsurvivors. Although the median survival after the second resection is 30 months, 20 of the 25 patients have had recurrences with a median disease-free interval of only 9 months. No characteristic of primary or metastatic disease predicted outcome, including time between presentation of the primary and development of liver metastases, disease-free interval after the first liver resection, and bilobar liver involvement. CONCLUSIONS: Although repeat liver resections can be performed safely and improves survival, the likelihood of cure from such resection therapy is low. This likelihood of further recurrences encourage studies of adjuvant or alternative treatments of this population.

Nativity, complications, and pathology are determinants of surgical results for gastric cancer.

BACKGROUND: About half the patients involved in the current study were born outside of the United States. Epidemiologic and histologic features and survival estimates were compared with persons born in the United States. Results of gastrectomy with lymph node dissection were studied. METHODS: Records of 187 patients with adenocarcinoma of the stomach were reviewed. Seventy-six with a curative gastrectomy were staged retrospectively. Univariate and multivariate analyses were done. RESULTS: Seventy-six percent of histologically reviewed curative resections had the intestinal subtype with the same frequency in U.S.-born and foreign-born patients. Fewer patients with proximal third lesions were foreign born. Thirty-six percent had complications. The overall 5-year Kaplan-Meier survival estimate was 46%: 77% for patients with negative nodes and 33% for patients with positive nodes. N1 survival estimate was 44%; N2, 25%; N3(M1), 0%. All six patients with early gastric cancer are alive 50-147 months after surgery. Other stage I patients had estimated survival of 65%; Stage II, 52%; Stage III, 40%; and Stage IV, 0%. Multivariate analysis revealed four significant prognostic variables: nativity, histologic subgroup, presence of complications, and number of positive nodes. CONCLUSIONS: Proximal gastric cancer was more common in U.S.-born persons. Gastric cancer may be more malignant in U.S.-born persons than in foreign-born persons because their survival was significantly poorer. Complications, a significant adverse factor, were more common in U.S. series. Pancreatectomy with gastrectomy is rarely indicated, because microscopic involvement is rare and complications frequent. The prognostic advantage of a regional lymphadenectomy remains unclear.